Disclosure requirements vary considerably from state to state, as ProPublica recently charted. In many cases, the rules have been limited by a “trade secrets” provision under which companies can claim that a proprietary chemical doesn’t have to be disclosed to regulators or the public.

One apparent proponent of the trade secrets caveat? The American Legislative Exchange Council, better known as ALEC, a nonprofit group that brings together politicians and corporations to draft and promote conservative, business-friendly legislation. ALEC has been in the spotlight recently because of its support of controversial laws like Florida’s “Stand Your Ground” provision.

This weekend, as part of a story on ALEC’s political activity, The New York Times noted that the group recently adopted “model legislation” on fracking chemical disclosure, based on a bill passed in Texas last year. According to The Times, the model bill was “sponsored within ALEC” by ExxonMobil, which runs a major oil and gas operation through its subsidiary, XTO Energy. The advocacy group Common Cause, which provided the documents on ALEC’s lobbying efforts to The Times, describes model legislation, in many cases identifying by name the company that proposed it to ALEC’s task forces.

ALEC has recently removed its list of model bills from its main website, and did not respond to requests for comment. A spokesman for XTO Energy confirmed that the company is a member of ALEC, but he did not provide details on the company’s involvement with the disclosure bill.

The spokesman said ExxonMobil supports “full disclosure of the ingredients and additives in hydraulic fracturing fluids,” but added that when vendors request it, ExxonMobil has “respected the trade secret status of their products.” Last year, the company began voluntarily uploading chemical disclosures to FracFocus, a clearinghouse website run by the Groundwater Protection Council and the Interstate Oil and Gas Compact Commission.